Regression Analysis Lesson 1

Problem:      A factory is producing and stockpiling metal sheets to be shipped to an automobile manufacturing plant. The factory ships only                                                                               when there is a minimum of 1000 sheets in stock at the beginning of that day. The table shows the day, x, and the number of                                                                               sheets in stock, f (x), at the beginning of that day.

 Day 1 2 3 4 5 6 Sheets in stock 350 456 555 689 777 865

Write a linear regression equation and use this equation to determine the day the sheets will be shipped.

Solution       The linear regression equation is: y=104.914 x + 248.13

Step 1:

Solution       To calculate the days the sheets will be shipped:

Step 2:            Substitute the value of x in the linear regression equation and calculate the value of y. The value of x for which y becomes                                                            equivalent to 1135.

Solution        y=104.914 x + 248.13

Step 3:            Put x=7.165

Then y= (104.914*7.165) + 248.13

Step 4:

Complete

Try two practice problems:

Solve the following:

The table shows the amount of Salt Dissolved in the water and that is given to the School Students in every 6 hours following a dose of 10 ml. It seems that the rate of decrease of the drug is approximately proportional to the amount remaining.

 Time (hrs) 0 1 2 3 4 5 6 7 8 Salted water amount(ml) 10 9.8 9.5 8.3 7.4 6.9 5.8 4.4 3.5

A.

Use this information to find a suitable function to model this data.

B.

Using your model, when will there be less than 1 ml. of the Salted water given to the Students?